Although there’s still many things we don’t know about about the Verizon iPhone — namely, in the details of their pricing and the generosity of their data plans — one immediate advantage Verizon has over AT&T is that you can tether up to five different devices to the handset’s 3G connection over WiFi, when AT&T only offers one.

For road warriors, that’s a big perk to the Verizon iPhone compared to the AT&T one: you can drive an entire mobile office with just one Verizon device. Another benefit is that AT&T tethering service only works via Bluetooth or USB.

So will AT&T cave and match Verizon’s offer? AppleInsider asked the question, and was told by an AT&T representative that they would not “speculate” on their own plans.

Fair enough, but it appears that AT&T might not have a choice: the Verizon iPhone’s Hotspot tethering app is actually a native component of iOS version 4.2.5 (the default OS build Verizon’s iPhones are running).

It seems likely, then, that as soon as the Verizon iPhone comes out, Apple will pump an official iOS update for all devices down the pipeline, bringing the Hotspot app to all devices, including iPads. Naturally, the carriers probably have some control over how a subscriber can use that Hotspot app on their existing plans, but it seems pretty likely that all iPhone owners will be able to tether their devices to their 3G connection via WiFi soon enough.